Objective 3: Application of the Model
The first step in applying the developed model to the study site is the identification of groups of wells. A grouping analysis tool was used to divide the points (wells) into clusters based on defined analysis fields. Analysis fields were created before running the tool by creating new point layers that divided the points into meaningful groups (groups within each analysis field were defined by an attribute). The first analysis field used a buffer analysis to create groups based on whether they were within 1/4, 1/2, 3/4, or over 3/4 of the total radial distance of the study area from the treatment plant. The second parameter grouped the wells based on concessions, such that wells within each concession were assigned to their own group.
Once these groups were defined, each was exported into its own data layer. Network analyst was used to create a tranportation route for each group (each layer) using the roads and individual group layers. Calculate field, a tool within model builder, was used to multiply the total length of each route by the cost per unit length of pipeline and output the total cost. This tool was again used to divide the cost of each route by the number of stops to provide the cost benefit value. The Merge Tool combined the cost-benefit values for all groups into one database table, and the Sort Tool sorted them from highest to lowest. The total cost of each network was carried over in addition to the cost-benefit value, and used in conjuection with a table listing the four budget scenarios to iterate comparing cost of the first route to the first budget, subtracting cost of the route if it was smaller than the budget, then repeating the process using the next route and new budget. The output from this tool is a string of six characters (presenting the six routes) denoting wheather each group is apart of the network or not (See Appendix). In addition to this, another tool uses a similar premese to output the residual of each budget after the desired routes are built.
Using the residual budget, the truck-cistern routes were created. Network analyst was again used to build a truck-cistern route for each of the remaining groups. To determine the cost of running a truck-cistern network, a case study from Spicewood, Texas was analyzed, as this area suffered a drought from 2011 to 2012. To satisfy the short-term water scarcity problem, water trucks delivered water from a nearby city to 935 households (United States Environmental Protection Agency, 2017). These trucks were able to deliver water on a weekly basis to all residents in Spicewood at a cost of 25,000 (CAN) per month (United States Environmental Protection Agency, 2017). Given the results of this case study, this model designated that the truck-cistern network will cost $300,000 annually to service this many households. This cost was scaled for each route based on the number of wells serviced by the route. From this case study, each truck has an inital cost of $200,000. The number of trucks require to satisfy the needs of each network is based off an assumed 10 minute delivery time and one delivery per well per week, therefore one truck is needed to service 350 homes. This will also be scaled to each network using the total number of wells from all group assigned to the truck cistern network in order to determine the initial cost of creating the network, however this scaled value will have to be rounded to an integer value (rounded up to ensure no shortage of service) (Figure 3). Output from this final section of the model is a length of time over which the created truck-cistern network can run based on the total number of wells on the network.
Figure 4 outlines the individual steps of the model operating under Budget #1 ($42,000,000).
Figure 4: A flow chart describing the specific steps taken and tools used to build the transportation network using the model. Budget #1 is used as an example.
By combining these nested networks into one, a complete water distribution network was created. After this model was applied to the Six Nations of the Grand River community, a theoretical network existed that connects the Six Nations of the Grand River community to the distribution plant via either pipeline or truck-cistern.